The Sibling
by Thorn17
Summary: Mycroft Holmes' life as the only Holmes prodigy is changed forever with the arrival of a baby boy; his younger brother Sherlock. What will happen as the two geniuses grow up together in the same household?
1. Chapter 1

The seven year old Mycroft Holmes stood in the sitting room, watching his seated Mummy make funny noises to the squirming bundle of blankets that she held in her arms. He could hear a faint gurgling noise that seemed to be coming from inside the blankets. Of course, the noise could just be the science experiment bubbling over in his bedroom, but that didn't seem very likely. Mycroft was always so careful when it came to carrying out experiments in the house. His heart sank as the baby that was swaddled in blankets began to emit a high-pitched squeal. He had been hoping - in vain, it seemed - that he would never have to hear that noise again, after it had kept him awake for many hours the previous night. Mycroft was now beginning to realise that this noise, and therefore this baby, were going to be permanent fixtures in his life. Ever since the baby had been born, it had stolen Mummy and Daddy's attention away from Mycroft, upsetting him greatly. In the space of a single night, the little boy had destroyed the progress Mycroft had been making in denying his _feelings_. They could not be categorised as simply one emotion; there was a mixture of sadness, anger and jealousy, alongside a little curiosity and innate brotherly love and rivalry.

"Mycroft, aren't you going to come and see your little brother?" asked Mummy, momentarily drawing her gaze away from the newborn son in her arms to look at his older brother.

Mycroft shook his head.

"Don't be silly, Mycroft," scolded Mummy. "Say hello to Sherlock."

Mycroft didn't really want to - he would much rather send the screaming baby back to wherever it was that it came from - but he found it hard to disobey Mummy. He could see by the slight twitch in the corner of Mummy's mouth that it was unlikely that she would leave the subject alone, but it was still worth a try.

"Don't want to." Mycroft crossed his arms sulkily and pulled a face. "What kind of a name is 'Sherlock' anyway?"

"A unique name for a unique little boy, just like your own name is. Come sit beside me, Mycroft." Mummy patted the spare sofa cushion beside her. The young Mycroft reasoned that the baby scared _him, _and that people liked company when they were scared, and so because Mummy wanted _Mycroft's_ company, she must be scared of the baby too. Mycroft wanted to protect his Mummy, and so he did as she asked and sat beside her. She lowered her arms, gently pulling a piece of the little blue blanket aside to give Mycroft a clearer view of the baby.

Mycroft had never seen anything like it before. The baby, his _brother_, was already beginning to grow dark brown hair upon his head, although Sherlock's was - at present - wispy and curly, not straight like his elder brother's. Sherlock had long thick eyelashes, which fanned around his light bluey-green eyes, creating a startling contrast. There was so much of Mummy in the baby's face that Mycroft couldn't help but care for the little boy, even if he hadn't already felt an innate connection with his brother. In that moment, Mycroft accepted Sherlock as part of his family, somebody worthy of his protection and guidance. Mummy had obviously failed to notice that Sherlock possessed the same keen intellect as Mycroft did, given by the silly noises and faces she was pulling to entertain the baby. Mycroft had always longed for somebody to sit down and explain to him _why _Mycroft could see and understand things in an instant that nobody else could. They never did. People thought that he was strange, that he should be left alone in the hope that he would grow out of it. From this moment onwards, the seven year old Mycroft promised that he would never let his brother suffer in the same way that he had been treated; as an outcast.

"Isn't he beautiful?" Mummy cooed.

Mycroft didn't give a verbal response, though he inwardly agreed. He felt uncomfortable answering such personal questions, ones which required him to reveal his own emotions to others. Daddy had taught Mycroft that showing emotions was not a good thing, because nasty people could use them against you. Mycroft had remembered what Daddy had said; Mycroft never forgot anything. Daddy was very clever, but never had a lot of time for Mycroft or Mummy. He was always at work, either 'in the office' or in his study. Mummy had once said that Daddy was an interrogator. Mycroft didn't know exactly what this was - nobody would tell him, and he wasn't allowed access to any resources that would help him define it - but he knew that it was an important job.

Mycroft continued gazing at his little brother, their eyes locked on each other in mutual understanding and brotherly affection. He was only just beginning to understand what Daddy had meant by 'the power of emotions'.


	2. Chapter 2

The Holmes family lived in a secluded area, their large estate surrounded by woods and lakes. A reasonable section of the land had been set aside by Mummy and Daddy - neither Mycroft or Sherlock felt ready to call them by their real names yet, not even 'Mum' or 'Dad' - as a garden for the boys to play in. The brothers had watched as Daddy had invented and fitted ingenious locks that he deemed to be child-proof to the gates. If Mycroft and Sherlock had been average children, then the locks would indeed have been child-proof. However, the boys were geniuses - prodigies almost - and so figuring out how to unlock the supposedly child-proof locks was child's play to them. Literally. The three year old Sherlock was proving to be adept at solving practical puzzles and challenges just like this one.

The ten year old Mycroft was in the sitting room, sat on the sofa whilst engrossed in a book. He was just about to read the reactions of the characters as the murderer in the book was revealed - Mycroft already knew who it was, he had known from the first few pages, but it was always interesting to observe how ordinary people reacted to such news - when his attention was distracted by the sight of his younger brother walking across the carpet, locks of his curly brown hair falling in front of his eyes. He was heading towards the garden. Mycroft sighed and put his book down before chasing after the young Sherlock. He would just have to wait to find out how the story would end. Mycroft had _told _his parents time and time again that Sherlock would figure out how to escape his room, even if they _did_ close the door properly. If child-proof locks were no restriction for the young boy, then getting through a closed door certainly wouldn't be.

"Sherlock, come back!" he called. The toddler could move surprisingly quickly, because by the time Mycroft had managed to catch up with him, they were already in the garden. Sherlock loved being outdoors, whereas Mycroft would opt to stay inside all the time if given the opportunity. The garden was usually out-of-bounds when Mummy and Daddy were not around to supervise their children's play, even when - like today - they were simply in another part of the house, because there were "so many dangers in the garden". Mummy and Daddy were scared that an enemy of Daddy's - one that he had made through his line of work - would take the boys and use them to blackmail their parents. Alternatively, the boys could become lost in the woods, or get into difficulty if they fell into a lake.

"No, Mycroft, I want to play outside." Sherlock sat cross-legged on the floor, wearing a pair of dungarees with a grey t-shirt underneath. His speech was advanced for his age, but - just as Mycroft had observed almost immediately after Sherlock's birth - the toddler possessed remarkable intellect. Mummy and Daddy were both clever, but Mycroft was not sure if they were the sole reason for such intelligent offspring. They may have provided the foundation, but Sherlock and Mycroft had taken it upon themselves to learn, observe and deduce as much as possible. While other children watched television or played dress-up, Sherlock and Mycroft read - with ease - books that were meant for children much older than themselves. They tested each other with quizzes and puzzles. Recently, Sherlock's favourite game had been '_Guess who?_', even though it was only intended for children over the age of six years.

"Sorry, Sherlock, you can't. We need to wait for Mummy and Daddy." Mycroft bent down and picked his younger brother up. Sherlock buried his face in Mycroft's shoulder.

"Please, Mycroft, I want to play pirates!"

In the garden, there was a wooden pirate ship, similar to those found in playgrounds or children's areas in pub gardens. Sherlock was besotted with it, and Mycroft was torn between relenting and letting his brother play, or disobeying Mummy and Daddy. Mycroft had always struggled when attempting to disobey Mummy or Daddy, and he had promised them that he would never play outside with Sherlock unsupervised. Mycroft thought it best to offer Sherlock an alternative, an appeasement gesture, rather than simply saying 'no'.

"Maybe later. How about a game of '_Guess who?_'" Mycroft carried Sherlock back into the sitting room, and gently placed him down on the soft carpet. Sherlock crossed his arms and frowned.

"Not baby," he said, gesturing towards himself. "That's a baby game."

Mycroft smiled. "It's meant for children over the age of six, Sherlock. You're only three. Trust me when I say it's not a baby game."

"It's boring. Boring baby game." Sherlock's smoky eyes fixed on Mycroft's with such stubborn determination that Mycroft knew it would take a lot of effort in order to convince his younger brother to stay indoors. Sherlock was prepared to argue with Mycroft for a long time in order to get his own way, but both boys became distracted by the sound of shouting coming from another room in the house. There were two distinct voices within the argument; one was Mummy and the other was Daddy. Mycroft turned his head in the direction of where the sound was originating from, and then back to his brother. Sherlock was scared. So was Mycroft, but he knew better than to show it. Even if he hadn't been told that showing emotion was bad from an early age, Mycroft felt duty bound to protect his brother, and showing his own fear would do nothing to help Sherlock. Mycroft had to remain strong. He had a good idea what was going on upstairs - a woman named Sarah had caused a lot of arguments between Mummy and Daddy recently - but thankfully Sherlock didn't understand. Not yet, anyway. Mycroft doubted that it would be long before he did, though.

Mummy and Daddy had always promised Mycroft that they would keep him safe, and nobody would hurt him, but _they _were hurting him emotionally, and so in Mycroft's mind they had broken their promise. If parents could break their promises, so could he.

"Do you still want to play pirates, Sherlock?"

The little boy nodded, a smile beginning to form on his face as he realised that he was getting his own way, that Mycroft was relenting. He didn't realise what was going on upstairs between his parents. Mycroft had been right. This wasn't unusual - Mycroft was always right - but it _was_ a relief for the elder brother.

"Come on then," said Mycroft, hurriedly picking his brother up and returning to the garden, away from the commotion. Sherlock didn't need to hear Mummy and Daddy's arguments, and Mycroft certainly didn't want to either. "Who do you want to be, Sherlock? Blackbeard or Long John Silver?"


	3. Chapter 3

"Mycroft, you're obviously too intelligent to be in this class," sneered Mr Logan sarcastically. "If you have time to stare absentmindedly out of the window, then surely you could spare the rest of us a few moments of your precious time to answer the question on the board."

The thirteen year old Mycroft didn't like it when teachers spoke to him like that. Sarcasm truly was the lowest form of wit. Every other student in Mycroft's class inhaled a sharp breath upon hearing Mr Logan's words. The question on the board was not difficult - Mycroft would truly be amazed if there was a student in the class who _couldn't _tell Mr Logan what the answer to the logarithm question was - but Mycroft's fellow classmates understood perfectly the enormous deductive feats that Mycroft was capable of. However, Mr Logan, as their mathematics class supply teacher, did not. Mycroft tried to restrain himself - it wasn't in his nature to show off his intelligence - but Mr Logan's next comment pushed the elder Holmes brother a little too far.

Mr Logan smirked. "I didn't think so." A triumphant grin began to spread across his face, though Mycroft failed to see why his teacher was gloating over supposedly being more intelligent than a student. Surely the role of the teacher was to _help_ those who did not understand something? Mycroftalready understood logarithms, but he was fairly certain that nobody else in the class did. "You should pay more attention in class, Mr Holmes. How can you possibly expect to understand something if you don't listen during my explanation?"

Mycroft snapped. He didn't like people making fun of him. He had enough of that at home, or when relatives came to visit, or when relatives came to visit and brought their narcissistic children along. "The answer is two point seven nine nine."

Each set of eyes in the class turned from Mycroft to Mr Logan in an instant, anticipating that their teacher's response would not be particularly pleasant. Mr Logan's face began to flush, and he clenched his fists a little. "You little cheat! You looked at the answer, you must have! I won't have a cheat in my class, get out! Go to the Head teacher's office at _once_!"

Mycroft rose from his chair calmly, picking up his school bag, coat and umbrella. "Certainly, Mr Logan. I must say, today's class has proved to be _extremely_ enlightening. As expected, you have failed to teach me any mathematics that I did not already know, but I _have _learned that you are currently going through a divorce, the proceedings of which were instigated by your wife when she discovered your extramarital affair a few weeks ago. You frequently drink alcohol to 'drown your sorrows' which causes your fiery temperament to flare up, therefore meaning that you are constantly in trouble with the police. You had a fight last night, with a man around the same height as you, maybe a little smaller, and you lost. That's why your fists clenched just now when I proved you wrong. Your knuckles are sore, scraped and bruised, and I believe the best term that I could use to describe you is 'a sore loser'. Oh, and quite frankly, I think my little brother could teach logarithms better."

Mycroft gave a small sneer before he left the classroom and headed towards the Head teacher's office. He could hear Mr Logan verbally venting his anger out on the rest of the class, and felt a twinge of regret for what they were experiencing. He quickly brushed this feeling aside. He should not be worried. Mycroft would, in due course, report Mr Logan to the Head teacher, she would caution him appropriately, and Mr Logan would consequently improve his behaviour. Even if the man didn't care about the welfare of his students, Mr Logan couldn't afford to lose his job.

Miss Adams was the Head teacher at Mycroft's school, but he had known her for much longer than the short period of time that he had been enrolled as a student there. _Sarah _Adams had been present in the lives of members of the Holmes family for just over three years now, since her affair with Mr Holmes had come to light. Mycroft didn't call him 'Daddy' any more. As far as Mycroft was concerned, Mr Holmes had lost his right to that title when he betrayed Mummy. In return for the family's silence on the subject - a prestigious school with a known adulteress for a Head teacher would not be received very well amongst the public - Miss Sarah Adams had offered both Holmes brothers places at her illustrious schools. Mummy had pressured the boys to accept the offers. She wanted the best education possible for her sons, even if this meant that they were educated by the woman who had wrecked her marriage. She would not allow her personal feelings to interfere with the futures of her offspring.

As he approached the office of the woman in question, Mycroft finished reminiscing and briskly knocked twice on Miss Adams' office door. He only knocked out of courtesy. He had been led to believe that this was the appropriate social norm, although Mycroft didn't see why he had to abide by it, given what Miss Adams had done to his family.

"Enter." Upon hearing this, Mycroft opened the door and stepped inside the office. Miss Adams was seated at her wooden desk, reading some paperwork. She barely looked up at the shadow in her doorway before speaking. "Ah, Mycroft, I was wondering how long it would be before we had another little chat."

"When this school stops employing imbeciles, we need never have another 'little chat' again."

Miss Adams sighed and looked over the top of her spectacles at Mycroft, raising a quizzical eyebrow. "Which teacher was it this time?"

"That fool who calls himself a mathematics teacher. Mr Logan."

"Why, what did he do?"

"He attempted to humiliate me in front of the class because I was too bored to pay attention to his tedious logarithm explanation. It's not my fault that I'm more intelligent than he is."

"Poor man," murmured Miss Adams.

"What do you mean?" Mycroft frowned. If he'd wanted to, Mycroft was more than capable of deducing what she had meant, but thought it best to let Miss Adams explain herself rather than letting him explain for her. People usually became annoyed when Mycroft did that.

"Anyone that tries to get the better of a Holmes does so at their own risk. How bad was the damage?" She was referring to how badly Mr Logan had reacted towards Mycroft's chastising.

Mycroft shrugged his shoulders. "Nothing too severe. The class were subjected to a little shouting spell as he vented his anger verbally, but that's all over now. If this happens again though, I suggest you fire him. Mr Logan is not a man who reacts well to criticism of any form, and goodness knows what his fiery temperament will cause him to do if pushed too far."

"He's not the only one around here that doesn't respond well to criticism though, is he, Mycroft?" Miss Adams raised an eyebrow pointedly, and it didn't take somebody with the intellect of Mycroft Holmes to understand to whom she was referring.

Mycroft was not particular affronted by her insinuation. "No, he is not, but _I _am perfectly capable of remaining in control at all times, unlike Mr Logan."

"Yes, the perfected aloof nature that you possess truly is a wonder in somebody so young." Miss Adams' tone suggested that she was experiencing a mixture of genuine wonder, resentment, but predominately bitterness towards the thirteen year old boy.

Mycroft refused to be intimidated by Mr Holmes' mistress. "Recent changes in my life have meant that it is vital for me to remain aloof, so that I do not become weakened by my emotions. Mummy, for example, is having a terribly hard time at the minute, and so I need to remain strong for her." This time it was Mycroft's turn to make a silent, acknowledged point about what Miss Adams had done to his Mummy. Both parties knew that they were only having this conversation in the first place because Mr Holmes and Miss Adams had become a little _too _friendly in the past.

The office telephone rang, startling both teacher and pupil. Mycroft read the look on Miss Adams' face almost as clearly as if he saw the words written down in front of him; _Phew, that was lucky! Saved by the bell. Well, almost._

"Good afternoon. Miss Adams - Head teacher - speaking." These were the words that Miss Adams spoke aloud, but Mycroft knew what she really meant. It was written all over her face, but even if it hadn't been, the nervous _tap-tap-tap _of her nails on the desk was an obvious clue that indicated that Miss Adams felt uncomfortable discussing her personal relationship with Mycroft's father in front of him. "Oh dear, I'm sorry to hear that. Is he alright?"

Normally, Mycroft would not have been concerned by Miss Adams' conversation, reasoning that it was very unlikely that the person who was evidently _not _alright was any concern of his. However, the atmosphere in the room changed quickly when Miss Adams began to emit concern for the person in question's wellbeing. Such emotional displays unnerved Mycroft when he was not in full possession of all the facts. "How dreadful! Please hold on a moment, and I will let him know." Before Miss Adams could speak, the voice on the phone demanded her attention again. Mycroft waited for a few moments, waiting for Miss Adams to speak again. When she did so, it was in a curt but caring tone. "Yes Mrs Holmes, I shall tell him now, during which time you can prepare some of Sherlock's belongings and take them with you."

_Mrs Holmes? Sherlock? _Mycroft felt a lump begin to form in his throat. Tears? Why would tears be forming before he even knew what had happened? Why would Mummy ring Mr Holmes' mistress with regards to a problem with Sherlock? Miss Adams had barely placed the phone back on the base before Mycroft spoke.

"What has happened?" He could see from Miss Adams' facial expression that it was not good news, whatever _it _was.

"Sit down, Mycroft."

"With all due respect, I don't _want_ to sit down! Why did Mummy telephone _you? _What has happened to my brother?"

"I'm afraid Sherlock has been taken to hospital, Mycroft. Another boy from his school started a fight with your brother, resulting in both parties being taken to the aforementioned hospital. Sherlock's injuries are serious, but thankfully he is stable at the moment. The other boy only received a few scratches."

"They're six year old boys, for goodness sake! Why were they fighting _at all_?"

"I don't know, but apparently Sherlock did not try to defend himself."

"_What_?" Mycroft couldn't comprehend why Sherlock would do such a thing. It wasn't logical, and it certainly couldn't have been out of consideration for anyone's _feelings_, which was another common downfall that people tended to experience. If Sherlock had wanted to protect somebody's feelings, he would have made an effort to protect himself, however feeble the attempt may have been.

"Your mother is coming to fetch you, and then you are both going to visit your brother. You can ask one of _them_ to clarify the situation, though it seems the eyewitnesses were pretty sure of what they saw."

"What about Mr Holmes? Is he coming too?"

"Sorry, Mycroft. _Daddy _is working."


	4. Chapter 4

**Author's Note: Apologies for the long delay in updating this story!**

"Excuse me! You can't just come barging in here. This is a hospital! There are sick children here!"

"Come back here at once, young man! I shall report you to security if you proceed any further!"

"You're not a patient, are you? Where is your mother, boy? She shouldn't be allowing you to roam around the hospital unattended. That's irresponsible parenting!"

Various members of hospital staff took it upon themselves to comment on Mycroft's abrupt arrival at the children's ward of St Bartholomew's Hospital. His entrance was about as subtle as a bulldozer tearing through the building unannounced. Despite his stormy, furious expression, a small part of his mind admired the dedication of the staff to the welfare of their patients, as his unexplained presence had admittedly caused quite a fuss, and he _was_ a security risk. He didn't care, and proceeded to ignore every protest that he encountered. He needed to see his brother and ascertain the seriousness of the situation for himself. Sherlock first, security and scolding later.

A sorrowful sight met Mycroft as he burst Sherlock's hospital room, located at the very end of a corridor within the ward. The boy had probably been allocated this room in order to keep him out of the way of the other patients, as Sherlock was never particularly subdued, even when asleep. It wasn't acceptable for him to disturb the other ill children. Even Mycroft could understand that. Upon arrival at the hospital, he'd convinced Mummy that she should wait outside and attempt to contact Mr Holmes again, and then follow him and deal with the mess he had left in his wake. Mummy had the authority to overrule the security guards that had undoubtedly been summoned, even though she scarcely chose to exercise this power.

It was a good job that he had organised that particular arrangement, because if Mummy set her eyes upon her youngest son while he was still in the state that Mycroft found him in, she would burst into tears. Mycroft wanted to do the same, but he refrained. He'd practised maintaing an aloof persona for years, even if on the inside his stomach was turning and a lump was forming in his throat. Mycroft was met with the sight of his sulking baby brother sat cross-legged upon the bed, having evidently refused to oblige the nurses who had wished him to remain laying. Sherlock's chestnut curls were tussled upon his head, and clumps of them were stuck together with a substance that, at first glances, appeared to be blood, though Mycroft couldn't tell whose blood it was. His skin was even paler than usual due to shock, which made it contrast starkly with the darkness of his hair. Although his head was lowered, Mycroft could see that Sherlock was sporting a black eye and a bruised, cut lip. The elder Holmes could also deduce that, given the angle of Sherlock's injuries, they had been inflicted by an assailant who was of a smaller height than Sherlock was. It was, therefore, illogical as to why Sherlock would not defend himself against a weaker opponent when he could have easily overpowered them, especially seeing as Sherlock and Mycroft had both attended various martial arts and self defense classes since they both turned four years old.

"What happened, Sherlock?" asked Mycroft gently as he approached the bed, switching his umbrella from his right hand to his left, thereby freeing it to tentatively touch Sherlock's shoulder in what he hoped would prove to be a reassuring gesture. Instead of flinching - as would be expected from a young child that had just experienced such an ordeal - Sherlock remained perfectly still, which only added to Mycroft's confusion.

"Don't want to talk about it."

Mycroft raised an eyebrow. "Well, that's unfortunate, because I do. As does Mummy."

Sherlock looked up and Mycroft tried not to wince at his first clear view of his little brother's injuries. They were horrifying to see on such a small child. "Mummy's here?"

"Of course. Where did you expect her to be?"

Sherlock shrugged. "Don't know. Just not here."

Realisation dawned upon Mycroft. The words that the little boy refrained from saying spoke a lot louder than those he had. Since their parents became estranged, Mummy rarely left the house, or even her bedroom. Her sobs echoed around the house at night, and as both Holmes brothers never needed much sleep, they heard every single one. "Well, she's outside. Would you like me to fetch her?"

"No!" Sherlock's eyes widened. "Please, Mycroft. Don't."

Mycroft raised an eyebrow. "Why not?"

Sherlock said nothing, and lowered his gaze again.

Mycroft sighed. "Very well, let's try something else, shall we? What's the name of the boy who did this to you?"

"Anderson. He's in my class at school. Don't know why. He's stupid, and I'm not, and I told him so."

Mycroft sighed softly. "Sherlock," he chastised, "we've had this discussion before. You can't go round telling people that they're stupid."

Sherlock looked up again, confusion evident in his expression. "Even if they are?"

"Even if they are," Mycroft confirmed, trying not to smirk at Sherlock's resultant pout. "That's why things like this happen," he said, gesturing to Sherlock's current predicament.

Sherlock rolled his eyes. "Anderson didn't do this to me because I called him stupid."

_Interesting_, thought Mycroft. Sherlock had refused to tell him something when asked to divulge the information, but he was perfectly happy to contradict his brother. _Will keep a mental note of this, as it may help in procuring information in the future. People don't seem to like telling you things, but they love to contradict you._ "Then why did he do it?"

"He did it because I told his girlfriend that he was cheating on her with another girl."

Girlfriend? Wasn't being a mere six years of age a little young for initiating relationships? Mycroft's brain couldn't process that particular piece of information. He couldn't rationalise it into any psychological theory he'd read about that attempted to explain human behaviour. Even at thirteen, Mycroft had never felt the need to embark on a relationship. Suddenly, as if a light had been switched on, Mycroft pieced everything together, and he understood what his brother had been trying to do, and why he had not defended himself against Anderson's attack.

Sherlock had told the girlfriend about Anderson's infidelity because he'd watched Mr Holmes' infidelity upset their mother, and Sherlock had decided that this girl didn't deserve that treatment. He'd done it to be kind and help her, not to be malicious. He'd thought that she would be grateful, and Anderson would be happy that he didn't have to keep lying to both girls any more to appease them. Sherlock had been wrong. Although _their father_ had been relieved when his sons had deduced his infidelity and told their Mummy, because it had meant that he wouldn't be the one to speak the words that would break her heart, Anderson hadn't reacted in the same way. He'd been angry at being found out, because he _wanted _to date two girls at the same time. Mr Holmes hadn't wanted to do that, he'd just been too cowardly to tell his wife that he loved another.

Therefore, Sherlock hadn't defended himself initially because he hadn't expected Anderson's attack, for their father hadn't attacked his sons when they revealed the truth, and Sherlock's mind was currently learning vicariously. Then, once it became apparent what Anderson was going to do, Sherlock had refrained from retaliating because he didn't want to upset their Mummy further. Sherlock's mind had rationalised that it was better she thought that he was a victim, rather than an instigator or trouble maker, because then she wouldn't be angry with him. Their father had instigated the trouble in their house, and they hated him for it. Sherlock was seeking approval, not rejection.

"Oh Sherlock," he said softly, retracting his hand from his brother's shoulder in order to sit beside him on the bed and carefully cuddle him close. "I see. I understand why you did it, brother, but you really shouldn't have done that."

"Why?" mumbled Sherlock against his brother's chest. "I wasn't lying. Everything I said is true."

"I know you weren't lying, Sherlock. I have no doubts that you were telling the truth, but it just wasn't your responsibility to tell the girlfriend. Anderson should have done that. In fact, Anderson should never have cheated on her in the first place. Monogamy is vital for successful relationships."

"By that logic, Daddy should have told Mummy that he was cheating, but he didn't. _You_ did, but that wasn't your responsibility either. You told Mummy that Daddy was cheating on her to stop her being sad all the time, so why can't I do the same to help somebody else and stop them being sad too?"

Mycroft sighed. "It's complicated, Sherlock, You're too young to understand."

Sherlock crossed his arms and humphed, burying his head further in Mycroft's shirt and wincing when he accidentally caught his injuries. "Mycroft, I'm six years old. I'm not a baby, and I'm not stupid."

"I know you're not," he said gently. In truth, Sherlock wasn't too young at all, and his mind was perfectly capable of comprehending Mycroft's explanations. However, Mycroft believed that excessive sentiment was a chemical defect found in the losing side - something which had seemingly been proven both here and at home - but reiterating this to his brother would cause him to be ostracised, just as his elder brother was in the process of being. Mycroft's peers were already wary of him. There was no need for Sherlock to endure the same, not if he could help it. He thought it best to change the subject at present. The bond between the two brothers allowed them to understand each other perfectly. "How did you know that he was cheating on her?"

Sherlock looked pleased that somebody was actually taking the time to listen to his deductions. They were undoubtedly impressive, but usually unwelcome in the eyes of the person whose life story had been deduced. Mycroft had noticed that Sherlock's deductions and observations were improving dramatically, though they had not quite reached his own standards.

"Because the black parts of his eyes got bigger when he saw both of them, and he kept breathing faster when both of them were present, and..." Sherlock pulled away from his brother's chest and continued to explain his reasoning, with a smile on his face and a twinkle in his eyes, his injuries forgotten.


End file.
